Why is Easter a "Moveable Feast"?

By Dr. Joan M. Kelly

Catholics can be forgiven for feeling a little disoriented each year as the dates for the beginning of Lent and Easter Sunday are always different. The question often asked — but rarely explained — is this: Why is Easter, unlike Christmas, a “moveable feast,” a date that changes year-to-year, and how is the date determined?

The answer involves tradition, and requires a lesson in the rich, sometimes turbulent, but always fascinating history of the Catholic Church. 

The Paschal Moon
The Council of Nicaea (325 A.D.) established the date of Easter as the first Sunday after the first full moon (known as the Paschal Moon) following the vernal equinox, the first day of Spring, when the sun crosses the equator and night and day are roughly the same length. In the West, which uses the Gregorian Calendar, the vernal equinox falls around March 21 (actually March 20 this year), so the date of Easter will fall, depending on the full moon, between March 22 and April 25.

The Paschal Full Moon this year is on April 1, and the first Sunday after the moon is April 5, Easter Sunday.

Not so in the East, where the Orthodox churches retain the older, Julian Calendar. This fixes the vernal equinox around April 3, so their celebration of Easter falls between April 4 and May 8. This year, the celebration of Easter in the East falls on our Divine Mercy Sunday, April 12. 

Why such a fuss about the vernal equinox and the moon?

Tradition. Since the dawn of civilization, calendars have been based upon the movements of the sun and the moon (from which we derive the word “month”). The Jews used a lunar calendar to fix the dates for Passover, after which Christians would celebrate Easter. 

The vernal equinox, moreover, held tremendous significance. For centuries, much of Europe celebrated the New Year at the vernal equinox, as late winter turns into springtime with signs of the rebirth of light, warmth, and life itself. The dark of winter gradually changing into the light of spring corresponds perfectly to the darkness of the Tomb passing into the light of the Resurrection! 

This newness of life fits in well with Easter. We even wear an Easter bonnet and outfit in imitation of the newly-baptized who came out of the water and put on new clothes, and we display Easter eggs as a symbol of new life. 

Obviously, once we have the date for Easter, the dates for Lent are also set. The name “Lent” is from the Middle English lenten and the Anglo-Saxon lencten, meaning spring; its most primitive ecclesiastical name was the “forty days,” tessaracoste in Greek. 

Forty days
Ash Wednesday marks the beginning of the 40-day liturgical season of fasting, special prayer, and almsgiving in preparation for Easter. The 40 days exclude Sundays and conclude on Holy Saturday, although Lent officially ends at noon on Holy Thursday, in preparation for the Easter Triduum. 

The pre-Easter fast in the first three centuries was observed especially by catechumens preparing for Baptism, and lasted only two or three days. It later developed into three or four weeks. The number 40 is first noted at the Council of Nicaea. Its canons speak of Lent as the quadragesima paschae, the 40-day period of preparation for Easter, imitating Jesus Who, after His Baptism in the Jordan, fasted for 40 days (Mt 4:2; Lk 4:1-2). The early Church Fathers also saw in the practice an echo of the 40 days Moses fasted on Mt. Sinai (Ex 34:28), and the 40 days Elijah fasted on his journey to Mt. Horeb (1 Kings 19:8), as well as the 40 years of Israel’s sojourn in the wilderness. 

The number 40 took a few centuries to become the norm. In some Eastern churches, the practice was five fast days per week for seven weeks (Saturday and Sunday excepted), making the total only 35. In Jerusalem in the fourth century, this meant five days’ fast for eight weeks, or 40 days, but in most of the West, this meant six days’ fast per week for six weeks, or 36 days. In the seventh century (600 A.D.), Pope St. Gregory the Great set Ash Wednesday as the first day of Lent, so the days from Ash Wednesday through the First Sunday were added to make 40. 

Fasting regulations today are much less stringent. Ash Wednesday and Good Friday are days of fasting and abstinence for all Catholics in good health between the ages of 14 and 59. This means one full meal and two smaller meals only, and no meat may be consumed. In addition, all Fridays during Lent are days of abstinence from consuming meat for everyone age 14 and higher. 

Times a’changing?
In modern times, there has been a growing desire for a fixed date for Easter, as there is for Christmas. The Second Vatican Council (1962-1965) issued an appendix to the Constitution on the Sacred Liturgy in 1963, which read as follows: 

The Sacred Second Vatican Ecumenical Council recognizes the importance of the wishes expressed by many concerning the assignment of the feast of Easter to a fixed Sunday and concerning an unchanging calendar. ... The sacred Council is not opposed to assigning the feast of Easter to a fixed Sunday in the Gregorian calendar, provided those whom it may concern give their assent, especially the brethren who are not in communion with the Apostolic See (e.g. Reformation Churches, Orthodox). 

Efforts have continued to keep this concern of a fixed date alive and to make Christians everywhere aware from time to time of the cogent arguments regarding this issue. 

The Easter Octave
Easter Sunday is not the end of our Easter celebration. It’s the first day of the Easter Octave, an eight-day period in which we continue to celebrate the Paschal Mystery, the Passion, death and Resurrection of Jesus. Each of the eight days of the Easter Octave is a solemnity, the highest-ranking feast day on which no other feast may be celebrated.

Liturgically the Easter Octave has always been centered on the theme of Divine Mercy and forgiveness, which is why the designation of Divine Mercy Sunday, which concludes the Easter Octave, makes so much sense. As Pope St. John Paul II pointed out in his Regina Caeli address on Divine Mercy Sunday, 1995, “The whole octave of Easter is like a single day,” and the Octave Sunday is meant to be the day of “thanksgiving for the goodness God has shown to man in the whole Easter mystery.” 

Contrary to popular belief, Divine Mercy Sunday is not an optional title for this solemnity; rather, Divine Mercy is the integral name for this Feast Day, which our Lord requested to St. Faustina: “It is My desire that it be solemnly celebrated on the first Sunday after Easter. Mankind will not have peace until it turns to the Fount of My mercy.” (Diary of St. Faustina Kowalska, 699)

The late Dr. Joan M. Kelly was a professor of Catholic studies at Sacred Heart University in Fairfield, Connecticut.

Photo by Ganapathy Kumar on Unsplash.
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